/**
 * Copyright &copy; 2012-2013 <a href="https://github.com/thinkgem/jeesite">JeeSite</a> All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 */
package com.srp.common.utils;

import org.apache.commons.lang.Validate;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.DisposableBean;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.context.annotation.Lazy;
import org.springframework.core.io.DefaultResourceLoader;
import org.springframework.stereotype.Service;

import java.io.IOException;

/**
 * 以静态变量保存Spring ApplicationContext, 可在任何代码任何地方任何时候取出ApplicaitonContext.
 */
@Service
@Lazy(false)
public class SpringContextHolderUtil implements ApplicationContextAware, DisposableBean {

	private static ApplicationContext applicationContext = null;

	private static Logger logger = LoggerFactory.getLogger(SpringContextHolderUtil.class);

	/**
	 * 取得存储在静态变量中的ApplicationContext
	 * @author wuxiaohua
	 * @date 2021/6/27 15:41
	 * @return ApplicationContext对象
	 */
	public static ApplicationContext getApplicationContext() {
		assertContextInjected();
		return applicationContext;
	}

	/**
	 * 获取系统根目录
	 * @author wuxiaohua
	 * @date 2021/6/27 15:42
	 * @return 系统根目录
	 */
	public static String getRootRealPath(){
		String rootRealPath ="";
		try {
			rootRealPath=getApplicationContext().getResource("").getFile().getAbsolutePath();
		} catch (IOException e) {
			logger.warn("获取系统根目录失败");
		}
		return rootRealPath;
	}

	/**
	 * 获取系统根目录
	 * @author wuxiaohua
	 * @date 2021/6/27 15:42
	 * @return 系统根目录
	 */
	public static String getResourceRootRealPath(){
		String rootRealPath ="";
		try {
			rootRealPath=new DefaultResourceLoader().getResource("").getFile().getAbsolutePath();
		} catch (IOException e) {
			logger.warn("获取资源根目录失败");
		}
		return rootRealPath;
	}
	

	/**
	 * 从静态变量applicationContext中取得Bean, 自动转型为所赋值对象的类型.
	 * @author wuxiaohua
	 * @date 2021/6/27 15:43
	 * @param name bean名称
	 * @return 赋值对象的类型
	 */
	@SuppressWarnings("unchecked")
	public static <T> T getBean(String name) {
		assertContextInjected();
		return (T) applicationContext.getBean(name);
	}

	/**
	 * 从静态变量applicationContext中取得Bean, 自动转型为所赋值对象的类型.
	 * @author wuxiaohua
	 * @date 2021/6/27 15:44
	 * @param requiredType 赋值对象class实例
	 * @return 赋值对象的类型
	 */
	public static <T> T getBean(Class<T> requiredType) {
		assertContextInjected();
		return applicationContext.getBean(requiredType);
	}

	/**
	 * 清除SpringContextHolder中的ApplicationContext为Null
	 * @author wuxiaohua
	 * @date 2021/6/27 15:46
	 */
	public static void clearHolder() {
		if (logger.isDebugEnabled()){
			logger.debug("清除SpringContextHolder中的ApplicationContext:" + applicationContext);
		}
		applicationContext = null;
	}

	/**
	 * 实现ApplicationContextAware接口, 注入Context到静态变量中.
	 * @author wuxiaohua
	 * @date 2021/6/27 15:46
	 * @param applicationContext
	 */
	@Override
	public void setApplicationContext(ApplicationContext applicationContext) {
		if (SpringContextHolderUtil.applicationContext != null) {
			logger.info("SpringContextHolder中的ApplicationContext被覆盖, 原有ApplicationContext为:" + SpringContextHolderUtil.applicationContext);
		}

		SpringContextHolderUtil.applicationContext = applicationContext;
	}

	/**
	 * 实现DisposableBean接口, 在Context关闭时清理静态变量.
	 * @author wuxiaohua
	 * @date 2021/6/27 15:48
	 * @throws Exception
	 */
	@Override
	public void destroy() throws Exception {
		SpringContextHolderUtil.clearHolder();
	}

	/**
	 * 检查ApplicationContext不为空
	 * @author wuxiaohua
	 * @date 2021/6/27 15:48
	 */
	private static void assertContextInjected() {
		Validate.notNull(applicationContext, "applicaitonContext属性未注入, 请在applicationContext.xml中定义SpringContextHolder.");
	}
}